The need for being able to distinguish valid signatures from those which have been forged has been well established in the fields of business and banking for quite some time. Costly experience has taught that even a careful study of an individual's signature by a merchant or a banker is not an adequate safeguard since a skilled forger can often fool anyone who is not a handwriting expert. The problem of discerning between a forged signature and a valid signature is a problem which many have attempted to solve in the prior art.
Many of the more modern attempts have recognized that an individual's signature has associated therewith several distinct characteristics which can be detected by some means or another and converted into electrical signals which can be automatically processed and compared with the stored representation of an authentic signature for determination as to whether or not the signature currently being investigated is authentic or is a forgery.
One of the characteristics of an individual's signature which has been the focus of considerably attention is the characteristic pressure which is produced when an individual signs his signature. While this type of characteristic is not discernable to one who studies the signature on a piece of paper or a document, it can be detected and stuided by other means. It has been found that the pressure variations produced when an individual signs his signature are characteristic of that individual's signatuure and can be used with an acceptable degree of accuracy for signature identification or verification purposes.